# Langfuse: Slow trace data retirival across API and UI in EU

- Impact (vendor’s label): minor
- Status: resolved · edited after publishing
- Started: 2026-10-21 07:15 UTC · Resolved: 2026-10-21 09:39 UTC · Duration: 2.4 h
- Updates: 5 · Affected components: Public API, Public API, LLM-as-a-judge, LLM-as-a-judge, UI
- [Vendor status page: https://status.langfuse.com/incidents/01M5EPTJX79TDVMB07KQV902HH](https://status.langfuse.com/incidents/01M5EPTJX79TDVMB07KQV902HH)
- [Company: Langfuse](https://rewindex.com/company/langfuse.md)

## Timeline of updates

- **investigating** 2026-10-21 07:46 UTC: Slow traces data serving across API and UI
- **identified** 2026-10-21 08:31 UTC: Slow clickhouse read replicas affecting performance across the service. Draining and replacing them.
- **resolved** 2026-10-21 08:45 UTC: All replicas look healthy again
- **monitoring** 2026-10-21 08:56 UTC: Looks like some timeout are still occurring. Monitoring.
- **resolved** 2026-10-21 09:39 UTC: should be finally resolved

## Rewindex changes for this incident

- 2026-10-21 08:33 UTC: [Incident updated: Slow trace data retirival across API and UI in EU](https://rewindex.com/change/rd0787bfdde7cc3.md)
- 2026-10-21 08:53 UTC: [Incident updated: Slow trace data retirival across API and UI in EU](https://rewindex.com/change/r12c0e4347f18f8.md)
- 2026-10-21 09:03 UTC: [Incident updated: Slow trace data retirival across API and UI in EU](https://rewindex.com/change/rf5d88f1b08338c.md)
- 2026-10-21 09:43 UTC: [Incident updated: Slow trace data retirival across API and UI in EU](https://rewindex.com/change/r4972a205f09b69.md)


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Canonical: https://rewindex.com/company/langfuse/incidents/01M5EPTJX79TDVMB07KQV902HH · Markdown: https://rewindex.com/company/langfuse/incidents/01M5EPTJX79TDVMB07KQV902HH.md · JSON: https://rewindex.com/api/v1/companies/langfuse/incidents/01M5EPTJX79TDVMB07KQV902HH · Generated 2026-10-22T00:41:50.328Z